Chromium is a chemical element with the symbol 24. It is the first element in group 6. It is a steely-grey, lustrous, hard and brittle transition metal Chromium is the main additive in stainless steel , to which it adds anti-corrosive properties. Chromium is also highly valued as a metal that is able to be highly polished. Polished chromium reflects almost 70% of the visible spectrum being reflected. The name of the element is derived from the Greek word χρῶμα, chrōma, meaning color because many chromium compounds are intensely colored.
Ferrochromium alloy is commercially produced from chromite or aluminothermic reactions and chromium metal by roasting processes followed by reduction with carbon. Chromium metal is of high value for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel (electroplating with chromium) together comprise 85% of the commercial use.
In the United States, trivalent is considered an essential nutrient in humans for insulin However, in 2014, the European Food Safety Authority , acting for the European Union, concluded that there was not sufficient evidence for chromium to be recognized as essential.
While chromium metal and Cr(III) ions are not considered toxic, hexavalent chromium , Cr(VI), is both toxic and carcinogenic. Abandoned chromium production sites often require environmental cleanup